Apparatus for facilitating the application and removal of nuts or the like



NOV. 29, 1966 KEL ET AL 3,287,999

APPARATUS FOR FACILITATING THE APPLICATION AND REMOVAL OF NUTS OR THE LIKE Filed Nov. 24, 1964 3 Sheets-Sheet 1 ATTORN EY Nov. 29, 1966 K. KRECKEL. ET AL 3,287,999

APPARATUS FOR FACILITATING THE APPLICATION AND REMOVAL OF NUTS OR THE LIKE Filed Nov. 24, 1964 5 Sheets-Sheet 2 FIG.

INVENTORS ATTORNEY 1966 K. KRECKEL ET AL 3,287,999

APPARATUS FOR FACILITATING THE APPLICATION AND REMOVAL OF NUTS OR THE LIKE Filed Nov. 24, 1964 5 Sheets-Sheet I5 United States Patent The present invention relates to an apparatus for facilitating the application and removal of nuts, split rings, diametral pins and similar fasteners. Such apparatus may be utilized on pressure vessels and on many other types of structures where nuts, split rings, diametral pins and similar fasteners are to be applied on the bolt-like carriers to form therewith connectors or couplings which must resist exceptionally large stresses.

It is an important object of the present invention to provide an apparatus for facilitating the application and removal of nuts or similar fasteners which is constructed and assembled in such a way that it may allow for simultaneous application or removal of two or more fasteners so that a single apparatus will suifice on a structure wherein a large number of fasteners must be applied or removed in order to provide a strong connection between two or more parts or to allow for rapid disconnection of such parts.

Another object of the invention is to provide an apparatus of the just outlined characteristics which may be manipulated in an exceptionally simple way, which facilitates practically effortless application or removal of nuts or similar fasteners, which is capable of determining in advance the force with which a nut may be driven home on a threaded bolt, shaft, spindle or a similar carrier, and which may be combined with many existing types of structures where two or more parts must be coupled to each other by bolts and nuts, bolts and rings or the like. A further object of the invention is to provide an improved tool which may be utilized in combination with the novel apparatus to effect rapid application or removal of nuts While such application or removal is being facilitated in accordance with our proposal.

An additional object of the instant invention is to provide a hydraulically or pneumatically operated apparatus for facilitating the application and removal of nuts from threaded bolts, shafts, spindles or similar carriers and to construct the apparatus in such a way that a single source of pressure fluid will suflice to facilitate the application or removal of two, ten, twenty or more nuts.

A concomitant object of the invention is to provide an apparatus of the just outlined characteristics wherein the majority of components are assembled into a compact and easy-to-handle unit which may be rapidly secured to or disconnected from a structure wherein two or more parts must be coupled to each other by a plurality of bolts and nuts, bolts and split rings or similar coupling devices.

Still another object of our invention is to provide the improved apparatus with an arrangement which enables an operator to rapidly determine the presence or absence of leaks, to determine the extent to which any selected bolt is tensioned and extended preparatory to the application or removal of a nut, and to construct the arrangement in such a way that its provision in the apparatus does not interfere with normal operation when one or more nuts or similar fasteners should be applied to or removed from threaded bolts or similar carriers.

Another object of the invention is to provide an apparatus of the above outlined characteristics which occupies little room, which occupies room that is normally available in pressure vessels and similar structures, which may be utilized with great advantage in nuclear reactors, and which enables an operator to subject each of a plurality of bolt-, shaftor spindle-like carriers to identical tension.

A more specific object of the invention is to provide an apparatus for facilitating the application and removal of nuts from heavy-duty threaded bolts which serve to connect the cover with the container of a pressure vessel in such a way that the coupling between the container and the cover is positively leakproof.

A further more specific object of the invention is to provide a hydraulically operated apparatus of the just outlined characteristics.

With the above objects in view, one feature of the present invention resides in the provision of an apparatus for facilitating the application and removal of nuts and analogous fasteners in structures wherein a series of elongated parallel carriers are anchored in and connect a supporting part with a supported part and wherein such carriers have fastener-receiving end portions which extend beyond an exposed side of the supported part. In one of its preferred forms, the apparatus comprises a housing arranged to be placed against or to be secured to the exposed side of the supported part, a plurality of tensioning units each including a cylinder member and a cooperating piston member with one of such members secured to the housing and the other member secured to the end portion of a carrier, fluid-receiving chambers of variable volume defined by the cooperating cylinder and piston members in such a way that the corresponding carriers are subjected to tensional stresses and their length increases automatically when the volumes of the respective chambers increase, a source of pressure fluid, and conduit means connecting the source with the chambers so that, on admission of fluid into and on resultant increase in volume of such chambers, the length of the corresponding carriers increases while the housing simultaneously presses the supported part against the supporting part to thus facilitate the application or removal of fasteners from the end portions of the carriers. 7

The novel features which are considered as characteristics of the invention are setforth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary top plan view of a pressure vessel wherein the cover supports an apparatus which is constructed in accordance with a first embodiment of the present invention;

FIG. 2 is an enlarged transverse section as seen in the direction of arrows from the line II-II of FIG. 1;

FIG. 3 is another enlarged transverse section as seen in the direction of arrows from the line IIIIH of FIG. 1; and

FIG. 4 is a fragmentary axial section through a modified apparatus.

Referring to the drawings, and first to FIGS. 1 and 2, there is shown a portion of a supporting part 2a which constitutes the container of a pressure vessel and which is coupled to a supported part 2 in the form of a cover or lid. The coupling means between the container 2a and cover 2 comprises a series of elongated parallel carriers 4 in the form of threaded bolts which are anchored in the container 2a and have end portions extending through and beyond apertures 2b in the form of bores provided in the marginal portion of the cover 2. The end portion of each bolt 4 comprises a first threaded section 4a which is adjacent to the exposed side 2c of the cover 2, and a second threaded section 4b which is provided at the free end of the respective bolt. E'ach threaded section 4a meshes with a fastener 13 in the form of a nut whose inner end face 13a is concave or convex and bears against the complementary face of an annular washer 13b abutting against the exposed side 20.

The apparatus for facilitating the application or removal of the nuts 13 comprises an annular base or housing 1 provided with equidistant holes 1a to accommodate portions of the bolts 4 and the nuts 13. The holes 1a are large enough to allow for rotation of the respective nuts 13. The exposed side 1b of the housing 1 is detachably connected with a series of annular cylinders 6 which, in the illustrated embodiment, are secured thereto by radially extending screws 7. Each cylinder 6 accommodates an annular piston 8 which surrounds with some clearance the end portion of the corresponding bolt 4 and has a conical or spherical end face 8a which abuts against a complementary conical inner end face 5a provided on a tension transmitting nut 5 or against a spherical washer similar to the washer 13b. Each cylinder 6 constitutes with the associated piston 8 a tensioning device and these members together define an annular fluidreceiving chamber 6a which communicates with a port 12 provided in the respective cylinder. The tension transmitting nuts 5 are in mesh with the outer threaded sections 4b of the respective bolts 4, and the cooperating conical faces 5a, 8a insure that each bolt 4 is automatically centered in the respective aperture 2b. Annular sealing rings 6b, 6c are provided around each chamber 6a to seal it and to prevent uncontrolled leakage of pressure fluid.

The ports 12 are connected with tees 12a forming part of a hydraulic circuit which comprises convoluted conduits 11 connecting the adjacent tees to each other. One of the tees 12a is connected with a nipple 10 which is coupled to a supply conduit 11a leading to a source 11b of pressure fluid and containing a pressure regulating valve 110.

The apparatus of our invention operates as follows:

When the operators desire to couple the container 2a with the cover 2, the latter is placed on top of the container in such a way that the end portion of each bolt 4 extends through and beyond one of the apertures 2b. The operators then place the washers 13b onto the exposed side 2c of the cover 2 so that each washer surroundsthe end portion of the corresponding bolt 4. In the next step, the nuts 13 are brought into mesh with the threaded sections 4a so that they abut against the respective washers 13b. The operators then place the housing 1 against the exposed side 2:: of the cover 2 so that each hole 1a accommodates a nut 13. The cylinders 6 are connected with the housing 1 before the latter is placed onto the exposed side 20, and each cylinder 6 accommodates the corresponding piston 8. The operators then apply the tension transmitting nuts 5 so that the conical or spherical face 5a of each nut 5 bears against the complementary face 8a of the corresponding piston 8 or washer. The nuts 5 may be driven home with considerable force since each thereof is readily accessible so that it may be rotated by a suitable wrench or the like. In a way, the nuts 5 secure the pistons 8 to the end portions of the corresponding bolts 4.

Once the nuts 5 are applied in a manner as shown in FIG. 1, the operators open the valve 110 so that the pressure fluid may flow through the conduits 11a, 11, tees 12a, ports 12 and into the chambers 6a to increase the volumes of these chambers whereby the pistons 8 move upwardly, as viewed in FIG. 2, and tension the bolts 4 so that the inner end faces 13a of the nuts 13 move away from the washers 13b. The chambers 6a remain filled with pressure fluid while the operators tighten the nuts 13 in the following manner: The periphery of the housing 1 is provided with cutouts or passages 15 each of which communicates with one of the holes In. Each nut 13 resembles a gear having axially extending external teeth 130 which may be brought in mesh with the teeth of a gear-shaped tool 14a mounted on an elongated shaft 14 having a specially conflgurated tip 14b which is guided in a bracket 16 secured to the periphery of the housing 1 1. The configuration of grooves 16a in the brackets 16 i is such that the tip 14b of the shaft 14 may slide into a 1 circular bore 16b of the corresponding groove 16a whereby the teeth of the tool 14a move in mesh with the teeth of the associated nut 13. If the shaft 14 is rotated, that nut 13 which meshes with the tool 14a will be driven home and will bear against the adjacent washer 13b. Once the nuts 13 are driven home all around the marginal portion of the cover 2,.the pressure inthe chambers 6a is relieved by manipulating the valve 11c whereby the bolts 4 tend to contract and force the inner end faces 13a of the nuts 13 into very strong compressive engagement with the outer end faces of the washers 13b so that the cover 2 is safely clamped on top of the container 2a.

In order to remove the nuts 13, the operators again admit pressure fluid into the chambers 6a so that the bolts 4 are caused to extend axially and to reduce the pressure between the nuts 13 and washers 13b whereby the tool 14a may be utilized again to loosen the nuts 13 with a minimum of effort. The cover 2 may be lifted off the container 2a upon removal of nuts 5 and housing 1,

followed by unscrewing of loosely applied nuts 13 and I by removal of the washers 13b.

The provision of the tool 14a is of particular advantage in nuclear reactors in which the operators must manipulate the covers of pressure vessels from a certain distance. yards long.

Of course, two or more operators may manipulate two or more tools 14a at a time so that the nuts 13 may be applied or loosened with little loss in time. The provision of such tools is of particular advantage when the bolts 4 are closely adjacent to each other, see FIG. 1. Thus, it would be rather ditficult to use regular hexagonal or square nuts because there would be little room to apply a customary wrench to engage the facets of such polygonal nuts.

FIG. 3 shows that the cover 2 is provided with blind bores 2d (only one shown) which may receive cylindrical locator pins 18. The conical upper portion of each pin 18 extends into a registering bore 1b in the housing 1. Such pins assist the operators in properly locating the housing 1 on the exposed side 20 of the cover 2. FIG. 3 also shows one of a series of handgrip members 17 which are secured to the housing 1 by screws 17a and enable the operators to lift the housing 1 off the cover 2. For

example, the housing 1 may be provided with two, three or more equidistant handgrip members 17a.

Referring again to FIG. 2, each piston 8 is provided with a tapped bore 19a which receives a screw 19 Whose tip bears against a ball valve 19b. The bores 19a communicate with the respective chambers 6a and the ball 1 valves 1% perform the function of vents.

The internal surfaces of the cylinders 6 are provided with annular recesses 9a each of which may receive a split ring 9 when the apparatus of our invention is tested to determine the presence of eventual leaks. In carrying out a test, the rings 9 are inserted when the housing 1 is detached from the cover 2 and the valve 11c is then caused to admit pressure fluid so that the pistons 8 bear against the rings 9 and a pressure gauge 11d will indicate whether or not the apparatus is leaking. The rings 9 are removed when the apparatus is in actual use. a portion of the conduit 11a may consist of flexible material. If after the use of this apparatus the operators wish to reduce the pressure in the system, they will manipulate a special valve as shown at 110.

Of course, the cylinders 6 may be made integral with the housing 1 and the pistons 8 may be made integral with the tension transmitting nuts 5. Also, it is equally pos- The shaft 14 may be several feet or several At least sible to modify the apparatus by reversing the positions of the cylinders 6 and pistons 8.

The apparatus of our invention may be used on pressure vessels and in all such structures where nuts or similar fasteners must be applied with a view to provide very tight and vibration-proof connections between a supporting part and a supported part. Thus, it frequently happens that the cover of a pressure vessel must be clamped down by very large nuts such as cannot be driven home by hand or by lightweight power-operated wrenches. The tool 14a will be applied to drive home the nuts, preferably also when the operators should remain at a certain distance from the nuts 13, for example, to avoid dangerous radiation in nuclear reactors or to avoid excessive heat in certain types of installations wherein the nuts must be applied with exceptionally large force to withstand high pressure which may arise due to admission of pressurized fluids or due to heating of contents to a high temperature.

By providing an apparatus which can simultaneously tension and lengthen a large number of bolts or similar carriers, we insure that each nut may be driven home with the same force so that the clamping action of each bolt-and-nut connection is substantially the same. Also, the entire apparatus may be mounted on or detached from a supported part with little loss in time; all that the operators have to do is to grasp the handgrip members 17 and to lift the housing 1 off the cover 2 when the latter is to be detached fi'om the container 2a.

In accordance with a slight modification of our invention which is shown in FIG. 4, the housing 101 is provided with cylinders 106 to receive pistons 108 whereby each cylinder defines with the corresponding piston two annular fluid-receiving chambers 106a, 106a. The chambers 106a, 106a communicate with ports 112, 112 to receive oil or another pressure fluid.

The apparatus of FIG. 4 will be utilized when the carriers must be subjected to exceptionally strong tensional forces. It will be readily understood that the fluid admitted into chambers 106a, 106a will produce a much stronger tensioning or lengthening force than a fluid admitted into a single chamber 6a. The pressure of fluid used in the apparatus of FIG. 4 need not be as high as when only a single chamber is used. For convenience, the apparatus of FIG. 4 will be referred to as having tensioning devices comprising cooperating cylinder members and piston members which define dual fluid-receiving chambers of variable volume whereby the chambers defined by any given pair of cylinder and piston members are spaced from each other in the axial or longitudinal direction of the respective carrier. Such dual chambers will be provided when the carriers are closely adjacent to each other so that the radial dimensions of the chambers cannot be selected at will.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An apparatus for facilitating the application and removal of nuts and similar fasteners in structures wherein a plurality of elongated bolt-like carriers are anchored in and connect a supporting part with a common supported part and wherein such carriers have fastener receiving end portions extending beyond an exposed side of the supported part, said apparatus comprising a common housing arranged to be placed against the common supported part, said common housing having a common supporting face adapted to abut against and be supported by said common supported part; a plurality of tensioning devices provided on said common housing, each including cooperating cylinder means and piston means with one of said means engaging said housing and the other of said means operatively connected to the end portion of a carrier, said cylinder and piston means together defining fluid-receiving chamber means of variable volume and said cylinder and piston means being arranged to subject the corresponding carriers to tensioning stresses and to increase the length of such carriers when the volume of the respective chamber means increases; a source of pressure fluid; and conduit means connecting said source with all of said chamber means so that, on admission of pressure fluid into and on resultant increase in the volume of said chamber means, the length of the carriers increases substantially equally and the housing substantially uniformly presses the supported part in a direction toward the supporting part to thus facilitate the application of fasteners to the end portions of the carriers, said cylinders transmitting pressure to said common housing which in turn by its common supporting face transmits such pressure to said common supported part thus tending to equalize the tension in each of said elongated bolts.

2. An apparatus for facilitating the application and removal of nuts and similar fasteners in structures wherein a series of elongated parallel bolt-like carriers are anchored in and connect a common supporting part with a common supported part and wherein such carriers 'have fastener-receiving end portions extending beyond an exposed side of the common supported part, said apparatus comprising a common housing arranged to be placed against the exposed side of the common supported part, said common housing having a common supporting face adapted to abut against and be supported by said common supported part; a. plurality of tensioning devices provided on said common housing each including a cylinder member and a cooperating piston member with one of said members engaging the housing and the other member operatively connected to the end portion of a carrier, said cylinder and piston members toget-her defining fluid-receiving chambers of variable volume and being arranged to subject the carriers to tensioning stresses and to increase the length of such carriers when the volume of the respective chamber increases; a source of pressure fluid; and conduit means connecting said source with said chambers so that, on admission of pressure fluid into and on resultant increase in the volume of said chambers, the length of the carriers increases and the housing presses the supported part against the supporting part to thus facilitate the application and removal of fasteners from the end portions of the carriers, said cylinders transmitting pressure to said common housing which in turn by its common supporting face transmits such pressure to said common supported part thus tending to equalize the tension in each of said elongated bolts.

3. An apparatus for facilitating the application and removal of nuts and similar internally threaded annular fasteners in structures wherein a series of elongated parallel bolt-like carriers are anchored in and connect a common supporting part with a common supported part and wherein such carriers have fastener-receiving threaded end portions extending beyond an exposed side of the supported part, said apparatus comprising a common housing arranged to be placed against the exposed side of the supported part and having holes for passage of end portions of the carriers, said common housing having a common supporting face adapted to abut against and be supported by said common supported part; a plurality of tensioning devices provided on said common housing each including an annular cylinder member and a cooperating annular piston member with one of said members engaging the housing and the other member operatively connected to the end portion of a carrier, said cylinder and piston members together defining annular fluid-receiving chambers of variable volume and being arranged to subject the carriers to tensioning stresses and to increase the length of such carriers when the volume of the respective chamber increases; a source of pressure fluid; and conduit means connecting said source with said chambers so that, on admission of pressure fluid into and on resultant increase in the volume of said chambers, the length of the carriers increases and the housing presses the supported part against the supporting part to thus facilitate the application and removal of fasteners from the end portions of the carriers, said cylinders transmitting pressure to said common housing which in turn by its common supporting face transmits such pressure to said common supporting part via said common supported part thus tending to equalize the tension in each of said elongated bolts.

4. An apparatus for facilitating the application and removal of nuts and similar fasteners in structures wherein a series of elongated parallel bolt-like carriers are anchored in and connect a common supporting part with a common supported part and wherein such carriers have fastener-receiving end portions extending beyond an exposed side of the supported part, said apparatus comprising a common housing arranged to be placed against the exposed side of the supported part, said common housing having a common supporting face adapted to abut against and be supported by said common supported part; a plurality of tensioning devices provided on said housing each including a cylinder member and a cooperating piston member with one of said members engaging the housing and the other member operatively connected to the end portion of a carrier, said cylinder and piston members together defining dual fluid-receiving chambers of variable volume and being arranged to subject the carriers to tensioning stresses and to increase the length of such carriers when the volume of the respective chamber increases, said dual chambers being spaced from each other in the longitudinal directions of the respective carrier; a source of pressure fluid; and conduit means connecting said source with said chambers so that, on admission of pressure fluid into and on resultant increase in the volume of said chambers, the length of the carriers increases and the housing presses the supported part against the supporting part to thus facilitate the application and removal of fasteners from the end portions of the carriers.

5. An apparatus for facilitating the application and removal of nuts and similar fasteners in structures wherein a series of annularly arranged elongated parallel boltlike carriers are anchored in and connect a common supporting part with a common supported part and wherein such carriers have fastener-receiving end portions extending beyond an exposed side of the supported part, said apparatus comprising a common annular housing arranged to be placed against the exposed side of the supported part and having holes for the passage of end portions of the carriers, said common housing having a common supporting face adapted to abut against and be supported by said common supported part; a plurality of tensioning devices provided on said common housing each including a cylinder member and a cooperating piston member Wit-h one of said members engaging the housing and the other member operatively connected to the end portion of a carrier, said cylinder and piston members together defining fluid-receiving chambers of variable volume and being arranged to subject the carriers to tensioning stresses and to increase the length of such carriers when the volume of the respective chamber increases; a source of pressure fluid; and conduit means connecting said source with said chambers so that, on admission of pressure fluid into and on resultant increase in the volume of said chambers, the length of the carriers increases and the housing presses the sup ported part against the supporting part to thus facilitate the application and removal of fasteners from the end portions of the carriers, said cylinders transmitting pressure to said common housing which in turn by its common supporting face transmits such pressure to said common supporting part via said common supported part thus tending to equalize the tension in each of said elongated bolts.

6. An apparatus for facilitating the application and removal of nuts and similar fasteners in structures wherein a series of elongated parallel bolt-like carriers are anchored in and connect a common supporting part with a common supported part and wherein suchcarriers have fastener-receiving end portions extending beyond an exposed side of the supported part, said apparatus comprising a common housing arranged to be placed against the exposed side of the supported part, said common housing having a common supporting face adapted to abut againstand be supported by said common supported part; a. plurality of tensioning devices provided on said common housing each including a cylinder member and a cooperatsource of pressure fluid; and conduit means connecting said source with said chambers so that, on admission of pressure fluid into and on resultant increase in the volume of said chambers, the length of the carriers increases and the housing presses the supported part against the supporting part to thus facilitate the application and removal of fasteners from the end portions of the carriers, said cylinders transmitting pressure to said common housing which in turn by its common supporting face transmits such pressure to said common supporting part via said common supported part thus tending to equalize the tension in each of said elongated bolts.

7. An apparatus according to claim 2 further comprising handgrip means secured to said common housing to facilitate its placing against or removal from the eX- posed side of the supported part.

8. An apparatus according to claim 2, further comprising locator pins secured to the supported part and extending into registering bores provided in said common housing.

9. An apparatus according to claim 2, further comprising pressure regulating valve means provided in said conduit means to facilitate the regulation of pressures prevailing in said chambers.

10. An apparatus as set forth in claim 9, wherein said conduit means comprises convoluted conduits and tees connecting such convoluted conduits to said cylinders so that each tee communicates with one of said chambers.

11. An apparatus for facilitating the application andv removal of threaded nuts and similar fasteners from a plurality of elongated bolts and like carriers mounted on a common base, comprising a common housing having a plurality of holes arranged to receive portions of such carriers and to accommodate fasteners in mesh with said portions of the corresponding carriers, said common housing having a common supporting face adapted to abut against and be supported by said common base; cylinders provided on said housing; pistons provided in said cylinders and defining therewith annular fluid-receiving chambers each of which surrounds that portion of the corresponding carrier which extends through the respective hole of said housing; tension transmitting members secured to the carriers and cooperating with said pistons to extend the carriers axially in response to admission of pressure fluid into said chambers; a source of pressure fluid; and conduit means connecting said source with said chambers whereby upon application of pressure fluid said cylinders will transmit such pressure to said common housing which in turn by its common supporting face will transmit such pressure to said common base thus 9 tending to equalize the tension in each of said elongated bolts.

12. An apparatus as set forth in claim 11 for facilitating the application and removal of externally toothed fasteners, wherein said housing is provided with cutouts each communicating with one of said holes, and further comprising a gear-shaped rotary tool arranged to extend through a selected cutout and to mesh With the corresponding fastener so that rotation of said tool will result in rotation of the fastener on the corresponding carrier.

13. An apparatus as set forth in claim 12, further comprising an elongated shaft for said tool so that the tool may be rotated from a desired distance.

14. An apparatus according to claim 11, wherein said common housing is an annular housing having a plurality of equidistant closely adjacent axially parallel holes.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES, JR., Examiner. 

1. AN APPARATUS FOR FACILITATING THE APPLICATION AND REMOVAL OF NUTS AND SIMILAR FASTENERS IN STRUCTURES WHEREIN A PLURALITY OF ELONGATED BOLT-LIKE CARRIERS ARE ANCHORED IN AND CONNECT A SUPPORTING PART WITH A COMMON SUPPORTED PART AND WHEREIN SUCH CARRIERS HAVE FASTENERS RECEIVING END PORTIONS EXTENDING BEYOND AN EXPOSED SIDE OF THE SUPPORTED PART, SAID APPARATUS COMPRISING A COMMON HOUSING ARRANGED TO BE PLACED AGAINST THE COMMON SUPPORTED PART, SAID COMMON HOUSING HAVING A COMMON SUPPORTING FACE ADAPTED TO ABUT AGAINST AND BE SUPPORTED BY SAID COMMON SUPPORTED PART; A PLURALITY OF TENESIONING DEVICES PROVIDED ON SAID COMMON HOUSING, EACH INCLUDING COOPERATING CYLINDER MEANS AND PISTON MEANS WITH ONE OF SAID MEANS ENGAGING SAID HOUSING AND THE OTHER OF SAID MEANS OPERATIVELY CONNECTED TO THE END PORTION OF A CARRIER, SAID CYLINDER AND PISTON MEANS TOGETHER DEFINING FLUID-RECEIVING CHAMBER MEANS OF VARIABLE VOLUME AND SAID CYLINDER AND PISTON MEANS BEING ARRANGED TO SUBJECT THE CORRESPONDING CARRIERS TO TENSIONING STRESSES AND TO INCREASE THE LENGTH OF SUCH CARRIERS WHEN THE VOLUME OF THE RESPECTIVE CHAMBER MEANS INCREASES; A SOURCE OF PRESSURE FLUID; AND CONDUIT MEANS CONNECTING SAID SOURCE WITH ALL OF SAID CHAMBER MEANS SO THAT, ON ADMISSION OF PRESSURE FLUID INTO AND ON RESULTANT INCEASE IN THE VOLUME OF SAID CHAMBER MEANS, THE LENGTH OF TEH CARRIERS INCREASES SUBSTANTIALLY EQUALLY AND THE HOUSING SUBSTANTIALLY UNIFORMLY PRESSES THE SUPPORTED PART IN A DIRECTION TOWARD THE SUPPORTING PART OF THUS FACILITATE THE APPLICATION OF FASTENERS TO THE END PORTIONS OF THE CARRIERS, SAID CYLINDERS TRANSMITTING PRESSURE TO SAID COMMON HOUSING WHICH IN TURN BY ITS COMMON SUPPORTING FACE TRANSMITS EACH PRESSURE BY ITS COMMON SUPPORTED PART THUS TENDING TO EQUALIZE THE TENSION IN EACH OF SAID ELONGATED BOLTS. 